I wouldn't say it's due to current implementation details. The specification for most Proxy operations just demands very complicated (and therefore slow) internal workflows. In performance-sensitive code, it's probably better to avoid using Proxies -- usually the same functionality can also be achieved using faster techniques (for example, your snippet looks like you could just put |origin| onto |target|'s prototype chain).
On Fri, Aug 5, 2016 at 10:21 AM, <cbr...@chromium.org> wrote: > Proxies and the Reflect functions are implemented in C++ which means that > currently there are two things that will cause a slowdown over the simple > delegator object that installs getters and setters: > 1. the optimizing compiler cannot inline or otherwise improve calls to > proxies > 2. calls to proxies will always be more costly since we have to jump from > the JavaScript world to the C++ world > > A minor difference from the nodes delegates is that you do a full-blown > [[HasProperty]] check with Reflect.has (which walks up the prototype > chain), while in the delegates implementation you only check this once if > you use the auto-setup. > If you care a bit less for some corner cases you can do a keyed-load from > the target (target[key]) and just assume that if it's undefined you have to > look it up on origin object. > > let me know if this helps. > > On Friday, August 5, 2016 at 6:49:09 AM UTC+2, Fangdun Cai wrote: >> >> >> - Node 6.3.1: >> - macOS: >> >> I try use proxies for my project and created the >> https://github.com/fundon/delegate-proxy. >> >> But results from the benchmarks, proxy is very slowly. >> >> How to improve it? >> Source code >> >> module.exports = function delegateProxy (target, origin) { >> return new Proxy(target, { >> get (target, key, receiver) { >> if (Reflect.has(target, key)) return Reflect.get(target, key, receiver) >> const value = origin[key] >> return 'function' === typeof value ? function method () { >> return value.apply(origin, arguments) >> } : value >> }, >> set (target, key, value, receiver) { >> if (Reflect.has(target, key)) return Reflect.set(target, key, value, >> receiver) >> origin[key] = value >> return true >> } >> }) >> } >> >> Benchmarks code, delegate-proxy VS delegates >> >> const Benchmark = require('benchmark')const delegate = >> require('delegates')const delegateProxy = require('..') >> const obj = {} >> const p1 = {}const d1 = delegateProxy(p1, obj) >> const d0 = {}d0.obj = objconst d = delegate(d0, 'obj') >> for (let i = 0, l = 1000; i < l; i++) { >> obj[`a${i}`] = i >> obj[`b${i}`] = function () {} >> obj[`c${i}`] = i >> d.getter(`a${i}`) >> d.method(`b${i}`) >> d.access(`c${i}`) >> } >> const suite = new Benchmark.Suite() >> >> suite >> .add('delegates#getter', () => { >> /* eslint no-unused-expressions: 0 */ >> d0.a0 === 0 ? 1 : 0 >> }) >> .add('delegateProxy#getter', () => { >> /* eslint no-unused-expressions: 0 */ >> d1.a0 === 0 ? 1 : 0 >> }) >> .on('cycle', event => { >> console.log(String(event.target)) >> }) >> .on('complete', function () { >> console.log('Fastest is ' + this.filter('fastest').map('name')) >> }) >> .run() >> const suite2 = new Benchmark.Suite() >> >> suite2 >> .add('delegates#method', () => { >> d0.b0() >> }) >> .add('delegateProxy#method', () => { >> d1.b0() >> }) >> .on('cycle', event => { >> console.log(String(event.target)) >> }) >> .on('complete', function () { >> console.log('Fastest is ' + this.filter('fastest').map('name')) >> }) >> .run() >> const suite3 = new Benchmark.Suite() >> >> suite3 >> .add('delegates#access', () => { >> d0.c0 = 1 >> }) >> .add('delegateProxy#access', () => { >> d1.c0 = 1 >> }) >> .on('cycle', event => { >> console.log(String(event.target)) >> }) >> .on('complete', function () { >> console.log('Fastest is ' + this.filter('fastest').map('name')) >> }) >> .run() >> const suite4 = new Benchmark.Suite() >> >> suite4 >> .add('Reflect#get', () => { >> Reflect.get(obj, 'a0') >> }) >> .add('obj#key', () => { >> /* eslint dot-notation: 0 */ >> obj['a0'] >> }) >> .add('obj.key', () => { >> obj.a0 >> }) >> .on('cycle', event => { >> console.log(String(event.target)) >> }) >> .on('complete', function () { >> console.log('Fastest is ' + this.filter('fastest').map('name')) >> }) >> .run() >> const suite5 = new Benchmark.Suite() >> >> suite5 >> .add('Reflect#has', () => { >> Reflect.has(d0, 'a0') >> }) >> .add('key in d0', () => { >> 'a0' in d0 >> }) >> .on('cycle', event => { >> console.log(String(event.target)) >> }) >> .on('complete', function () { >> console.log('Fastest is ' + this.filter('fastest').map('name')) >> }) >> .run() >> const suite6 = new Benchmark.Suite() >> >> suite6 >> .add('Reflect#set', () => { >> Reflect.set(obj, 'a0', 2) >> }) >> .add('obj#key=', () => { >> /* eslint dot-notation: 0 */ >> obj['a0'] = 2 >> }) >> .on('cycle', event => { >> console.log(String(event.target)) >> }) >> .on('complete', function () { >> console.log('Fastest is ' + this.filter('fastest').map('name')) >> }) >> .run() >> >> Results >> >> delegates#getter x 2,414,206 ops/sec ±0.81% (83 runs sampled) >> delegateProxy#getter x 1,383,270 ops/sec ±0.94% (84 runs sampled) >> Fastest is delegates#getter >> delegates#method x 4,707,516 ops/sec ±6.25% (53 runs sampled) >> delegateProxy#method x 1,339,755 ops/sec ±6.93% (65 runs sampled) >> Fastest is delegates#method >> delegates#access x 2,427,859 ops/sec ±8.88% (67 runs sampled) >> delegateProxy#access x 1,344,403 ops/sec ±10.72% (47 runs sampled) >> Fastest is delegates#access >> Reflect#get x 7,481,142 ops/sec ±2.35% (82 runs sampled) >> obj#key x 35,676,972 ops/sec ±0.73% (83 runs sampled) >> obj.key x 35,687,692 ops/sec ±0.65% (82 runs sampled) >> Fastest is obj.key,obj#key >> Reflect#has x 8,369,451 ops/sec ±4.04% (77 runs sampled) >> key in d0 x 10,618,353 ops/sec ±7.39% (51 runs sampled) >> Fastest is key in d0 >> Reflect#set x 6,356,287 ops/sec ±7.22% (56 runs sampled) >> obj#key= x 32,970,782 ops/sec ±1.74% (82 runs sampled) >> Fastest is obj#key= >> >> -- > -- > v8-users mailing list > v8-users@googlegroups.com > http://groups.google.com/group/v8-users > --- > You received this message because you are subscribed to the Google Groups > "v8-users" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to v8-users+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. 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